XAMDataGrid：在网格内拖动行

Question

我正在使用XamDataGrid v14.2，并希望添加在数据网格内拖放行的功能。

我已经浏览了Infragistics论坛的帖子，但是大多数代码示例显示了将行从一个网格拖放到另一个网格。

是否可以在同一网格内拖放行？我要实现的效果是移动Web公告行号的顺序。

以下是网格外观的图像：

Answer 1

几个月前，我在Infragistics Forums上发布了具有某种行为的示例，该示例对与您的要求类似的行进行了重新排序。

相关标记：

<igDP:XamDataGrid DataSource="{Binding Items}" IsSynchronizedWithCurrentItem="True" GroupByAreaLocation="None">
    <i:Interaction.Behaviors>
        <DragGrid:XamDataGridDragDropBehavior/>
    </i:Interaction.Behaviors>
</igDP:XamDataGrid>

行为的C＃代码：

using System;
using System.Collections.Generic;
using Infragistics.Windows.DataPresenter;
using System.Windows.Interactivity;
using System.Windows;
using Infragistics.DragDrop;
using System.Windows.Input;
using Infragistics.Windows;
using System.Collections;
using System.Windows.Media;
using System.Reflection;

namespace DragGrid
{
    public class XamDataGridDragDropBehavior : Behavior<DataPresenterBase>
    {
        private DataPresenterBase dataPresenter;

        protected override void OnAttached()
        {
            base.OnAttached();
            dataPresenter = this.AssociatedObject;
            EventManager.RegisterClassHandler(typeof(XamDataGrid), UIElement.MouseLeftButtonDownEvent, new MouseButtonEventHandler(XamDataGrid_MouseLeftButtonDown));
            var dataPresenterStyle = new Style(typeof(DataRecordPresenter));
            dataPresenterStyle.Setters.Add(new EventSetter(FrameworkElement.LoadedEvent, new RoutedEventHandler(OnRecordPresenterLoaded)));
            dataPresenter.Resources.Add(typeof(DataRecordPresenter), dataPresenterStyle);
            DropTarget dropTarget = new DropTarget() { IsDropTarget = true };
            DragDropManager.SetDropTarget(dataPresenter, dropTarget);
        }

        private void OnRecordPresenterLoaded(object sender, RoutedEventArgs e)
        {

            var recordPresenter = sender as DataRecordPresenter;

            if (DragDropManager.GetDragSource(recordPresenter) != null)
            {
                return;
            }

            var dragSource = new DragSource
            {
                IsDraggable = true
            };

            dragSource.DragStart += new System.EventHandler<DragDropStartEventArgs>(dragSource_DragStart);
            dragSource.Drop += OnRecordDragDrop;
            dragSource.DragTemplate = ((Window)Utilities.GetAncestorFromType(this.dataPresenter, typeof(Window), true)).Resources["dragTemplate"] as DataTemplate;

            DragDropManager.SetDragSource(recordPresenter, dragSource);
        }

        void dragSource_DragStart(object sender, DragDropStartEventArgs e)
        {
            ArrayList draggedItems = new ArrayList();
            List<IList> sourceList = new List<IList>();
            SelectedRecordCollection selectedRecords = this.dataPresenter.SelectedItems.Records;
            DataRecord lastSelectedDataRecord = null;
            foreach (Record r in selectedRecords)
            {
                DataRecord dr = r as DataRecord;
                if (dr != null)
                {
                    lastSelectedDataRecord = dr;
                    draggedItems.Add(dr.DataItem);
                    sourceList.Add(GetSourceList(dr));
                }
            }
            DraggingData data = new DraggingData();
            data.Items = draggedItems;
            data.Lists = sourceList;
            if (lastSelectedDataRecord != null && lastSelectedDataRecord.ParentRecord != null)
            {
                data.SourceProperty = lastSelectedDataRecord.RecordManager.Field.Name;
            }
            e.Data = data;
        }

        private IList GetSourceList(DataRecord record)
        {
            IList retVal = null;
            DataRecord parent = record.ParentDataRecord;
            if (parent == null)
            {
                // There is no parent, use the grids list
                retVal = this.dataPresenter.DataSource as IList;
            }
            else
            {
                object parentDataItem = parent.DataItem;
                Type dataItemType = parentDataItem.GetType();
                PropertyInfo listProperty = dataItemType.GetProperty(record.RecordManager.Field.Name);
                retVal = listProperty.GetValue(parentDataItem, null) as IList;
            }
            return retVal;
        }

        private void OnRecordDragDrop(object sender, DropEventArgs dragInfo)
        {
            var result = VisualTreeHelper.HitTest(dragInfo.DropTarget, dragInfo.GetPosition(dragInfo.DropTarget));
            var targetElement = Utilities.GetAncestorFromType(result.VisualHit, typeof(DataRecordPresenter), true) as DataRecordPresenter;
            if (targetElement != null)
            {
                DataRecord targetRecord = targetElement.DataRecord;
                IList targetList = GetSourceList(targetRecord);
                object targetItem = targetRecord.DataItem;
                Type targetType = targetItem.GetType();
                DraggingData draggedData = dragInfo.Data as DraggingData;
                if (draggedData != null)
                {
                    IList itemsList = draggedData.Items;
                    object firstItem = itemsList[0];
                    IList<IList> listsList = draggedData.Lists;
                    if (!targetType.IsInstanceOfType(firstItem))
                    {
                        // the target type doesn't match the items we are dropping, get the child list from the parent if we have a property.
                        if (draggedData.SourceProperty != null)
                        {
                            PropertyInfo listProperty = targetType.GetProperty(draggedData.SourceProperty);
                            targetList = listProperty.GetValue(targetItem, null) as IList;
                            if (targetList != null)
                            {
                                for (int i = itemsList.Count - 1; i >= 0; i--)
                                {
                                    object currentItem = itemsList[i];
                                    int targetIndex = targetList.IndexOf(targetItem);
                                    listsList[i].Remove(currentItem);
                                    targetList.Add(currentItem);
                                }
                            }
                        }
                        else
                        {
                            MessageBox.Show("Can't drop here");
                        }
                    }
                    else
                    {
                        for (int i = itemsList.Count - 1; i >= 0; i--)
                        {
                            object currentItem = itemsList[i];
                            int targetIndex = targetList.IndexOf(targetItem);
                            listsList[i].Remove(currentItem);
                            targetList.Insert(targetIndex, currentItem);
                        }
                    }
                }

            }
        }

        void XamDataGrid_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            if (this.dataPresenter.Equals(sender))
            {
                DataRecordPresenter drp = Utilities.GetAncestorFromType(e.OriginalSource as DependencyObject, typeof(DataRecordPresenter), true) as DataRecordPresenter;
                if (drp != null)
                {
                    // If we already have a selection then we don't want the Grids SelectionController to be called which will cause a capture of the mouse and prevent dragging.
                    if (drp.IsSelected)
                    {
                        e.Handled = true;
                    }
                }
            }
        }

    }
}